Can women who are breast-feeding
use a levonorgestrel intrauterine system? What is the impact of fluconazole
(Diflucan, Pfizer; New York City), an oral medication used to treat vaginal
yeast infections, on oral contraceptive (OC) efficacy?

Comments are offered by
David Archer, MD, professor of obstetrics and gynecology and director
of the Clinical Research Center at the Eastern Virginia Medical Center in Norfolk;
Linda Dominguez, RNC, NP, assistant medical director of the Albuquerque-based
Planned Parenthood of New Mexico; Andrew Kaunitz, MD, professor and assistant
chair in the obstetrics and gynecology department at the University of Florida
Health Science Center/Jacksonville; and Susan Wysocki, RNC, NP, president
and chief executive officer of the Washington, DC-based National Association
of Nurse Practitioners in Women’s Health.

Question: I work
as a nurse practitioner in a small health department, and we see patients wanting
the Mirena (levonorgestrel intrauterine system [LNG-IUS], Berlex Laboratories,
Montville, NJ). It is listed in the package insert to avoid breast-feeding mothers
due to the levonorgestrel component. I think it would be a good method at six
weeks out for a postpartum mother whether she is breast-feeding or not. I need
backup. Can you help?

Wysocki: The Geneva-based
World Health Organization (WHO) lists use of the LNG IUS [at] six weeks postpartum,
the same as for progestin-only OCs.1

Question: What impact
does fluconazole have on OC efficacy?

Archer: There are
two papers on the pharmacokinetics of ethinyl estradiol with the administration
of a single and multiple doses of fluconazole.2,3 Both papers indicate
an increase in the serum levels of ethinyl estradiol after administration of
fluconazole.

One article also investigated
the effect of fluconazole on norethindrone and found a similar increase in serum
levels after fluconazole administration.2 These two articles would
indicate that there is no loss of efficacy of the contraceptive steroids with
the concomitant administration of fluconazole, even at high doses.

Dominguez: In regard
to OC failure issues, clinicians recognize that any negative health or psychosocial
change can be an impediment to correct contraceptive use.

If a sexually active woman
is preoccupied and suffering the unpleasant symptoms of genital itching and
discharge, she may well be less alert to utilizing her contraceptive pill, patch,
ring, or barrier method and less inclined to have sexual relations.

It is recognized that vulvovaginal
candidiasis is likely to flare around menses/withdrawal bleed time because of
the increase in the glycogen-rich vaginal environment. If a woman is dealing
with vaginal symptoms, she may be distracted from starting a new pack or ring/patch
cycle and have a prolonged hormone-free interval.

Kaunitz: Two well-designed
pharmacokinetic trials have found that estrogen and progestin levels are NOT
lowered in OC users administered fluconazole.2,3 Of note, steroid
levels are increased with use of the oral antifungal agent. Therefore, use of
fluconazole will not increase risk of contraceptive failure, but it might increase
risk of side effects in OC users.

Wysocki: WHO does
not list fluconazole in its list of OC/drug interactions, and it makes a special
point about long-term use of the drugs they do list.1 Fluconazole
is generally taken in one dose for the treatment of vaginal candidiasis.